1. Field of the Invention
The present invention is directed to a fluid supply cup for a fluid applicator, more particularly to a paint supply cup for a paint sprayer.
2. Description of the Related Art
Fluid is typically delivered to fluid applicators, such as paint sprayers, in one of three ways. For large applications which do not require frequent fluid change, the fluid may be fed through a hose connected to a remote pressurized source. For smaller applications, such as automobile painting and repainting in body shops, the fluid is generally placed in a cup attached to the sprayer. Commonly, the cup is suspended below a front end of a body on the sprayer and the fluid is fed to a nozzle by suction or aspiration induced by atomization air flow through the sprayer. This type of sprayer is commonly referred to as a suction feed sprayer. For viscous fluids and for sprayers operating at low air pressures, the cup may be pressurized to increase the fluid application rate. Finally, a cup is sometimes mounted above the sprayer body to feed the fluid via gravity to the sprayer so that less air pressure is needed to aspirate the paint, usually referred to as a gravity feed sprayer.
For supply-cup types of sprayers, it is important that the supply cup and sprayer be free from contamination, especially in painting applications, wherein it is particularly important to avoid contamination between batches so that the desired paint color is achieved for each batch.
Disposable cups and liners have been developed to avoid contamination between batches and to minimize the amount of cleaning needed between applications.
U.S. Pat. No. 5,816,501 to LoPresti et al. teaches a disposable collapsible liner for a suction feed sprayer, wherein the liner is within a paint jar and paint is drawn through a feed tube. However, the liner is subject to being drawn into the tube opening via suction, which can block the flow of paint through the tube.
U.S. Pat. No. 5,582,350 to Kosmyna et al. teaches a non-disposable gravity feed paint cup with a disposable liner. The liner requires the installation of a port with a special tool and takes considerable time and effort. Further, the liner is hard to remove without spilling paint into the paint cup, which requires cleaning of the cup.
U.S. Published Applications U.S. 2003/0006311 and U.S. 2002/0134861 and International Published Application WO 02/072276 teach gravity feed paint cup assemblies with disposable liners. However, these applications require the assembly of several parts by the operator to ensure the paint cup is sealed, taking up valuable time. Additionally, the assembly is made of several injection molded pieces which are relatively expensive, especially if the parts are disposable instead of being reused.
What is needed is a disposable fluid supply cup that is easy to assemble by an operator, and that can be disposable without being overly expensive.